What is the correct punctuation for Sam will go into water?

The correct punctuation for "Sam will go into water" depends on the context. Here are some possibilities:

* Sam will go into water. (This is a simple declarative sentence, so it ends with a period.)

* Sam will go into water, but only if it's warm. (This is a compound sentence, so it uses a comma before the conjunction "but.")

* "Sam will go into water," said the lifeguard. (This is a quote, so it uses quotation marks.)

Without more context, it's impossible to know for sure what the correct punctuation is.